Magnetizing apparatus



June 19, 1956 G. A. MITCHELL ET AL 2,751,526

MAGNETIZING APPARATUS 2 Sheets-Sheet 1 Filed April 13, 1954 INVENTORS. TCHEL L G.A.M/

BY A/ 1/ V037 Arr V June 1956 G. A. MITCHELL ET AL 2,751,526

MAGNETIZING APPARATUS 2 Sheets-Sheet 2 Filed April 13, 1954 INVENTORS G. ,4. M/ TCHEL L,

BY A/ M 70:57

Arr y MAGNETIZING APPARATUS Gerald A. Mitchell, White Bear Lake, and Norman V. Yost, St. Paul, Minn., assignors to Western Electric Company, Incorporated, New York, N. Y.,.a corporation of New York Application April- 13, 1954, Serial No. 422,728

Claims. (Cl. 317-203) This invention relates to magnetizing apparatus, and more particularly to apparatus for magnetizing Alnico magnets of magnetrons.

An object of the invention is to provide apparatus for passing high currents through the cores of magnets to magnetize them.

Another object of the invention is to provide apparatus for passing high currents through pairs of magnets secured to magnetrons after the magnets have been brazed to the magnetrons to magnetize the magnets.

A further object of the invention is to provide a magnetizing apparatus which may be quickly assembled and disassembled for loading and unloading, and also may carry very large currents for magnetizing.

An apparatus illustrating certain features of the invention may include a pair of blocks having sockets therein connected to bus bars of the opposite polarity, and highly conductive cores having tapered ends are inserted into the sockets in upright positions after a magnetron having a permanent magnet to be magnetized on each side thereof has been mounted on the blocks. A spanning bar then is located on the cores and is locked thereto, and clamps pivotally secured to the blocks are actuated to lock the assembly together, after which a large current is passed through the cores and the spanning bar to magnetize the magnets.

A complete understanding of the invention may be obtained from the following detailed description of an apparatus forming a specific embodiment thereof, when read in conjunction with the appended drawings, in which:

Fig. l is a partially sectional front elevation of an apparatus forming one embodiment of the invention;

Fig. 2 is a side elevation of the apparatus shown in Fig. 1, and

Fig. 3 is a horizontal section taken along line 3--3 of Fig. 1.

Referring now in detail to the drawings, there is shown therein an apparatus for magnetizing Alnico magnets and 11 of a magnetron 12, and, to magnetize the magnets 10 and 11, the magnetron is placed in a position resting on blocks 14 and 15 composed of insulating material secured to copper conductive blocks 16 and 17, respectively. The blocks 16 and 17 are provided with conical sockets, of which a conical socket 18 is shown, having soldered thereto liners 19 composed of a copperchrornium alloy which is highly conductive and sparkresistant, such as, for example, Mallory metal. The conductive blocks 16 and 17 are mounted on a non-magnetic base 21 and have copper bus bars 22 and 23 secured thereto. The conductive blocks are insulated from the base by insulating plates 25 and 26 so that the base does not form a conductive path between the two blocks 16 and 17. An insulated block 28 locates the blocks 16 and 17 precisely on the base 21. Knockout and cleaning holes 24 and 27 are provided in the blocks 16 and 17 and the base 21.

After the magnetron is placed on the insulating blocks .14 and .15 with openings 29 and 30 in the magnets 10 andllaligned withthesockets 18, copper cores 31 and 32'having frustoconically tapered ends 33 mounting frus- .toconical sleeves 34 soldered rigidly thereto are placed in=the liners :19sothat the .cores .3land 32 are in upright positions extending through the openings 29 and 30 .in the magnets 10 and 11. Thin coverings 35 of insulating materiaion the-peripheries of :the cores 31 .and 32 prevent sparking'between the.cores and then-iagnets .10 and 11. .Thesleeves 34 are complementary in shape to :the liners 19 and areof thesametmetal as the liners '19. .A spanning bar 36 composed of copper then is placed on the-cores 31 and 32 to .connectithemtogetherwelectrically. Shanks 39 of the cores .31 .-and=32 :fitclosely into sockets .40 in'the:spanningbarfifi :Thcn -yokes 42tand 43 .composed Of -non-.magnetic material zan'd secured pivotally to the blocks 16 and 17 by pins 45 are swung over the spanning bar 36, and knobs 48 and 49 are turned to push cap screws 50 downwardly against insulating plates 54 and 55 to form good electrical contact between the spanning bar 36 and the cores 31 and 32 and between the cores and the liners 19. Pulling brackets 51 and 52 having locating notches 58 therein serve to correctly position the yokes 42 and 43 initially.

To magnetize the magnets 10 and 11, D. C. power is applied to the bus bars 22 and 23 and current of about 150,000 amperes flows between the bus bars through a path including the block 16, the core 32, the spanning bar 36, the core 31 and the block 17, all in series, and the high current flowing through the cores 31 and 32, which are highly conductive, magnetize the Alnico magnets 10 and 11 to produce the polarity desired. The current then is turned off, and the yokes 42 and 43 are released from the spanning bar and swung to the sides of the apparatus, after which the spanning bar 36 is lifted away from the cores 31 and 32, the cores are removed from the blocks 16 and 17, and the magnetron 12 is removed from the apparatus, after which the operation described hereinabove may be repeated.

Each element of the apparatus is composed of a nonmagnetic material so that there is no hysteresis in the apparatus, and the conductivity thereof is constant. The apparatus has a constant resistance so that results are uniform, and may be quickly assembled and disassembled.

It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

1. An apparatus for magnetizing magnetron magnets, which comprises a pair of copper sockets insulated electrically from one another, a base mounting the sockets, a pair of copper bus bars connected to the sockets, a pair of copper legs each having one end portion designed to fit into the sockets, a copper spanning yoke for connecting electrically the other ends of the legs, and non-magnetic means secured to the base for pressing the yoke against the legs and the legs against the sockets.

2. An apparatus for magnetizing magnetron magnets, which comprises a pair of copper terminals insulated from one another and having tapered sockets, a base supporting the terminals, a pair of non-magnetic bus bars connected to the terminals, a pair of copper legs each having one end portion tapered to fit into the sockets, a copper spanning yoke for connecting electrically the other ends of the legs, and non-magnetic means secured to the base for pressing the yoke against the legs and the legs into the sockets.

3. A magnetizing apparatus, which comprises a pair of precisely spaced conductive copper blocks having conical openings lined with an alloy of copper and chromium, a pair of replaceable upright copper legs each of which has a conical end covered with an alloy of copper and chromium and also being provided with a boss on the opposite end, insulating coverings on the portions of the legs intermediate the ends thereof, a copper spanning bar having sockets for receiving in close-fitting engagement the bosses, a pair of pivotal yokes of non-magnetic material swingable over the ends of the bar, non-magnetic means carried by the yokes for pressing the bar against the legs and the legs against the conductive blocks, and means for applying a voltage across the blocks.

4. A magnetizing apparatus, which comprises a pair of precisely spaced electroconductive blocks having conical openings lined with an alloy of copper and chromium, a pair of replaceable upright copper legs each of which has a conical end covered with an alloy of copper and chromium and also being provided with a boss on the opposite end, electrically insulating coverings on the portions of the legs intermediate the ends thereof, a copper spanning bar having sockets for receiving the bosses, non-magnetic means for pressing the bar against the legs and the legs against the conductive blocks, and nonmagnetic means for applying a voltage across the blocks.

5. A magnetizing apparatus, which comprises a base, a pair of non-magnetic electroconductive sockets mounted on the base and insulated therefrom, non-magnetic insulating means mounted on the sockets, a removable U- shaped non-magnetic electroconductive bar, and nonmagnetic electroconductive means for electrically detachably connecting the arms of the bar Within the sockets.

References Cited in the file of this patent UNITED STATES PATENTS 534,802 Lemp Feb. 26, 1895 2,202,884 Zuschlag June 4, 1940 2,442,808 Granberry June 8, 1948 

5. A MAGNETIZING APPARATUS, WHICH COMPRISES A BASE, A PAIR OF NON-MAGNETIC ELECTROCONDUCTIVE SOCKETS MOUNTED ON THE BASE AND INSULATED THEREFROM, NON-MAGNETIC INSULATING MEANS MOUNTED ON THE SOCKETS, A REMOVABLE USHAPED NON-MAGNETIC ELECTROCONDUCTIVE BAR, AND NONMAGNETIC ELECTROCONDUCTIVE MEANS FOR ELECTRICALLY DETACHABLY CONNECTING THE ARMS OF THE BAR WITHIN THE SOCKETS. 